In devices such a server, a router, a storage, and etc. that process high rate signals at several G bit/s or more, a differential interface standard (for example, LVDS (Low Voltage Differential Signaling)) is adopted, and differential signals are transmitted between the devices or between respective circuit substrates in the devices, using a differential signal transmission cable. The differential signals have an advantage of having a high resistance to incoming noise, while achieving reduction in system power supply voltage.
A conventional differential signal transmission cable includes an insulated wire in which a pair of signal line conductors arranged in parallel is coated by an insulator, a shield tape wound around the insulated wire, and a retention tape wound around the shield tape. The retention tape is spirally wound around the shield tape.
According to U.S. Pat. No. 7,790,981 (Patent Document 1), a plus (positive) signal and a minus (negative) signal having phases inverted by 180 degrees to each other are transmitted to the pair of signal line conductors included in the differential signal transmission cable. Based on a potential difference of these two signals at a signal level (plus signals and minus signals), the signal level can be recognized at a receiving side, for example, when the potential difference is plus as “High” and when the potential difference is minus as “Low”.